The availability of commercial instrumentation for detection of ligand binding, based on the phenomenon of plasmon resonance, has resulted in extensive use of this technique to study ligand binding. The advantages of this approach are: 1) one need not identify a spectroscopic property of the ligand or the dialysis; 2) binding experiments can be performed rapidly; 3) the technique is extremely sensitive and requires only modest quantities of ligand and acceptor; 4) one can determine association constants over a wide range of concentration. This proposal requests support for acquisition of a BIAcore 3000 plasmon resonance instrument that will be part of an institutional proteonomics facility. Projects of five NIH-funded major users and five minor users are described. At present, this type of instrumentation is not available at the Medical College of Ohio or at any neighboring institution. The availability of this type of state of the art instrumentation will aid NIH supported investigators significantly in pursuing the aims of their research projects [unreadable] [unreadable]